emailben

Emailben is an open-source framework for evaluating email infrastructure and deliverability. It provides a modular set of tests and simulations intended for mail administrators, developers, and researchers to assess how an email setup performs in real-world conditions. The project focuses on inbox placement, authentication, encryption, and compliance with best practices, rather than on sending or routing mail itself.

Core components include test suites for SPF, DKIM, and DMARC alignment; MX and DNS configuration checks; TLS capability and certificate validation; SMTP behavior under varying conditions; and deliverability metrics such as mailbox placement probability and bounce characteristics. It supports reproducible testing via containerization and configuration files, with results exported as machine-readable reports.

Development and governance: Emailben originated from a community-driven effort in the early 2020s and is maintained under an open-source license. It is developed by volunteers and affiliated organizations. The project emphasizes transparency, reproducibility, and privacy; tests can be run against owned domains or test accounts with anonymized data.

Limitations and reception: The project is not a delivery system; it cannot solicit or receive mail on behalf of a real domain. Some users report complexity and resource requirements for large-scale tests. It has been used in academic and industry contexts to compare deliverability practices and to illustrate how configuration choices affect inbox placement.